The present invention is in the field of and relates to vehicle safety shut down for vehicles equipped with a passive keyless entry and start (PKES) systems. The described functionality is designed to prevent accidental and unintended prolonged idling of an engine in a vehicle equipped with a PKES system.
Modern vehicle incorporate a number of sophisticated electronics control systems to enhance vehicle functions and features and to provide added convenience to users. A primary control system of importance to manufacturers and owners is the access and engine start authorization system. Vehicle engine starter systems have advanced from simple starter motor designs using a physical ignition key to close a circuit to power the starter and crank the engine, to more sophisticated remote start systems with digitally encoded RF signaling to ignition systems, to more advanced keyless transponder based push to start systems. Recently, car manufacturers have introduced Passive Keyless Entry and Start systems that allow users to open vehicle doors and start their cars while having their car keys in their pockets. This feature is very convenient for the users since they don't have to search for their keys when approaching or preparing to start the car. One of the first passive keyless entry systems of this nature was disclosed in U.S. Pat. No. 4,942,393 issued to Warakasa et al. Since then, similar systems have been developed by a number of manufacturers including those disclosed in U.S. Pat. Nos. 5,973,611; 5,838,257 and 5,552,641.
Push-button keyless entry and start systems are very convenient and simple to use. A small radio frequency transmitter or transponder, generally built into a fob that is in the possession of the user, and which is activated with motion by the user, transmits a short range radio signal with an encrypted digital key. A series of LF (low frequency 125 kHz) antennas are located both inside and about the vehicle. External antennas are located in the vehicle door handles. As the user moves about with the fob, the motion activates the fob transmitter to transmit a short rang RF signal. If the fob is in proximity of the vehicle, generally three to six feet, receivers in the vehicle will receive the digital key transmitted by the fob and if the transmitted key is properly authenticates by the receiver the vehicle will passively unlock the vehicle door. The driver enters the vehicle and positions behind the wheel, with the key fob in the driver's possession. The vehicle's system recognizes the presence of the fob, and the driver only needs to depress the brake pedal, and push a button on the control panel to start the motor. The transmission of the digital key conveniently allows the driver to keep the key fob in their pocket when unlocking, locking and starting the vehicle. A signal from a fob with an invalid or unauthorized digital key will not allow for the unlocking of the doors or starting of the vehicle, and can trigger an alarm system or even disable the engine. This way, if someone enters the car without a valid key fob, the vehicle will remain secured.
The method of locking vehicle doors upon exit varies among designs. When leaving a vehicle equipped with a PKES key system, the vehicle doors are locked by either pressing a button on one of the door handles, touching a capacitive area on a door handle, or by simply walking away from the vehicle and distancing the fob from the proximity of the vehicle so that the doors lock when the signal is out of range of the antenna.
Although PKES systems are convenient, there remains a significant limitation with current PKES systems when it comes to shutting down the vehicle engine. In current systems, shutting off the engine is accomplished by pressing the start/stop button, usually located on the dash of the vehicle. Generally, the engine will remain running unless the start/stop button is depressed, even when the driver has exited the vehicle and removed the fob from proximity of the vehicle. Often, in modern vehicles with low noise, the driver cannot hear the motor, or the driver may be distracted when exiting the vehicle causing the driver to fail to depress the start/stop button and leaving the vehicle engine running.
In addition to the obvious adverse environmental impacts due to excess release of emissions, leaving a vehicle idling unattended may present a safety concern. Long term idling of the engine within a confined space, such as a within a garage attached to a dwelling, can lead to a rise in carbon monoxide levels that might potentially cause asphyxiation, brain damage or death to individuals exposed to high concentrations of carbon monoxide inside the dwelling.
To mitigate the risk of injury or death from unintended engine run in a confined space, and to reduce unintended emissions or a waste of fuel, disclosed is a new method and device for vehicles with PKES systems that is available for aftermarket installation. The engine idle protection system of the present invention is designed to work with vehicles that are factory equipped with push to start PKES systems. The current invention may be implemented after the original purchase of the vehicle or during manufacturing of the vehicle.
A number of systems have been developed to automatically shut down an engine. For example, U.S. Pat. No. 5,219,413 discloses a system that uses an infrared sensor to monitor temperature levels within the cabin of a vehicle which is presumed to represent the presence of a driver. There are other known systems primarily intended start/stop of vehicles that are being driven in heavy traffic conditions, and if a driver stops at a traffic light or other extended period during congested traffic condition, the engine is automatically shut off and then re-started to allow continued driving when the light has changed or when traffic congestion has eased. An example of such a system is U.S. Pat. No. 7,458,353. These systems have a number of limitations and fail to properly monitor all driving conditions to appropriately shutdown or prevent the shutdown of the motor under specified conditions. For example, it may be desirable to remote start a vehicle and allow for the idling of the engine without the presence of the driver.
U.S. patent application Ser. No. 12/708,981 also discloses an anti-idle control system and method of controlled engine shut down. However that system is limited in that it is simply timer base and relies on mechanical relays inserted into the ignition wire to shut down the engine. This is of no assistance in PKES system. Further the Dupuis et al application relies on a physical key being in the ignition in the on position and collection of multi-signal consensus process that requires a resolution of all primary sensor signals to be positive in order to support the engine shutdown. This is of no added value in a PKES system and will cause a number of engine runs when not necessary.
In view of the foregoing background, the present invention overcomes the limitations of the prior art by providing for an automated vehicle shut down method and device for shutting down a vehicle having a PKES ignition system where the engine has unintentionally been left running.
In one aspect of the current invention a method and device is disclosed for providing automatic engine shutdown for vehicles with a PKES system when a driver leaves the vehicle removing the PKES system remote from the proximity of the vehicle and inadvertently leaving the engine running.
In another aspect of the current invention a method and device are disclosed for monitors for the presence of the driver having a fob for a PKES system to determine if the vehicle has been left running unintentionally.
In a third aspect of the invention a method and device is disclosed for providing overriding factory PKES systems to add aftermarket engine shutdown and user notification features.
In yet another aspect of the invention a method and device is disclosed that provides audible, visual and electronic notification to a driving or the driver's electronic device that the vehicle having a PKES system has been left running and that the engine will be shut off unless the shutdown sequence is deactivated. If the shutdown fails by any malfunction, the system will go into an alternative notice mode.